On 13/12/2016 00:23, Dave Plowman (News) wrote:
Got a set of Xmas lights. Gawd knows how they do them at the price.
Blue and White. PS/controller gives a variety of programmes. Including
flashing the blue and white alternately, or all on together. But only two
wires from the PS. I can see reversing the polarity could have one colour
or the other, but how both at once with no apparent flicker? Fast
switching?


Julian Ilett explains two-wire pulse-controlled RGB LEDs here. Not sure
if your blue/white is exactly the same.

https://www.youtube.com/watch?v=gxdgRHmOuIo

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